/Engine/Source/Runtime/AugmentedReality/Public/ARBlueprintLibrary.h
On ARCore platform, you can leave the PhysicalWidth to 0 if you don't know the physical size of the image or the physical size is dynamic. And this function takes time to perform non-trivial image processing (20ms - 30ms), and should be run on a background thread.
A `UARCandidateImage_ Object pointer if the underlying ARPlatform added the candidate image at runtime successfully. Return nullptr otherwise.
static [UARCandidateImage](API\Runtime\AugmentedReality\UARCandidateImage) * AddRuntimeCandidateImage ( [UARSessionConfig](API\Runtime\AugmentedReality\UARSessionConfig) * SessionConfig, [UTexture2D](API\Runtime\Engine\Engine\UTexture2D) * CandidateTexture, [FString](API\Runtime\Core\Containers\FString) FriendlyName, float PhysicalWidth )